Primary Objective: use immunofluorescence (IF) on previously obtained biopsies to analyze and quantify changes in adipose tissue of subjects injected with poly-L-lactic acid (PLLA) or saline.

Sixteen female adults that participated in SPLASH study will be enrolled in this retrospective study. It aims to analyze previously collected biopsy samples from participants who completed the "SPLASH: Split-Body Randomized Clinical Trial of Poly-L-Lactic Acid for Adipogenesis and Volumization of the Hip Dell" study. The study will use immunohistology to assess changes in adipose tissue associated with treatment with PLLA (poly-L-lactic acid). We hypothesize that specimens treated with PLLA will be found to have more adipocyte-derived stem cells and preadipocytes undergoing mitosis and differentiation compared to control specimens.

Inclusion Criteria:

• Subjects who completed all biopsies in the previous SPLASH trial "A Single Center, Double- Blinded, Split-Body, Randomized Clinical Trial of Injectable Poly-L-Lactic Acid for Volumization and Adipogenesis of the Hip Dell - Protocol Number Sculptra-Hip-Dell-2021-12" .

Exclusion Criteria:

• Subjects who had biopsies of poor quality, insufficient tissue, or were otherwise unsuitable for immunofluorescence analysis.

Previous study was only done on females due to skin quality and aesthetic concerns

16 Females that were previously enrolled and biopsied in SPLASH study.